Characterization of a Polymeric Food Tray Proposed for Military Use

摘要

The U.S. military utilizes a wide variety of food packaging systems to deliver rations to soldiers throughout the world. Food products and packaging systems must be capable of withstanding large variations in humidity, temperature and extended storage, as well as distribution related shock and vibration. Currently, polymeric trays are being evaluated to ensure their military suitability under each of these rigorous conditions. In addition, it was necessary to determine the thermal stability, assess the thickness and the uniformity of various tray layers. The potential also exists that polymeric additives are capable of migrating from polymeric trays, thus becoming food additives. Chemical migration evaluations were conducted by way of soxhlet extractions of the polymeric tray with both 5 percent acetic acid and chloroform. Gas chromatography-mass spectrometry evaluation of chloroform extracts indicated the presence of aliphatic hydrocarbon oligomers from the polypropylene tray. Several antioxidants were also observed in the chloroform extracts. Analysis by differential scanning calorimetry (DSC) showed that the trays were stable at minimum and maximum temperatures. The DSC data showed that the thermal processing of the polymeric tray had a minimal effect on crystallinity. Scanning electron microscopy (SEM) revealed the quantitative thickness of the various layers.